Mike Miller wrote:
(Henry Spencer) wrote in message ...


More recent landers, e.g. Mars Pathfinder, generally have *not* been
sterilized, because it is now fairly certain that conditions on the
Martian surface are so hostile that it's virtually impossible for Earth
organisms to survive and spread.


Well, you learn something every day.

Old: clean. New: sloppy.

Still, the end result is the same. Some terrestrial contamination has
already made it to Mars.

Terrestrial contamination occurred over billions of years through
meteorite transfer Earth - Mars along the reverse process that brings
Mars meteorites to Earth. Micro-organisms do survive the transfer.

Dan